Laravel validation - comma separated string input as array - php

Question

How can I validate one input with multiple values? I'm using bootstrap tagsinput plugin. It returns all tags in one field. I need to validate this tags - unique.
First I'm trying to place this tags into array and then validate it in request but still no luck.
Here is my code in request:
public function all()
{
$postData = parent::all();
// checkbox status
if(array_key_exists('keywords', $postData)) {
// put keywords into array
$keywords = explode(',', $postData['keywords']);
$test = [];
$i = 0;
foreach($keywords as $keyword)
{
$test[$i] = $keyword;
$i++;
}
$postData['keywords'] = $test;
}
return $postData;
}
public function rules()
{
$rules = [
'title' => 'required|min:3|unique:subdomain_categories,title|unique:subdomain_keywords,keyword',
'description' => '',
'image' => 'required|image',
'keywords.*' => 'min:3'
];
return $rules;
}
But as soon as keyword becomes invalid I get this error:
ErrorException in helpers.php line 531:
htmlentities() expects parameter 1 to be string, array given.
Any ideas what's wrong?

Answer 1

I was running into a similar problem with comma separated emails on 5.4. Here's how I solved it:
In your request class, override the prepareForValidation() method (which does nothing by default, btw), and explode your comma separated string.
/**
* #inheritDoc
*/
protected function prepareForValidation()
{
$this->replace(['keywords' => explode(',', $this->keywords)]);
}
Now you can just use Laravel's normal array validation!
Since my case needed to be a bit more explicit on the messages, too, I added in some attribute and message customizations as well. I made a gist, if that's of interest to you as well

Answer 2

Instead of mutating your input, for Laravel 6+ there is a package to apply these validations to a comma separated string of values:
https://github.com/spatie/laravel-validation-rules#delimited
You need to install it:
composer require spatie/laravel-validation-rules
Then, you can use it as a rule (using a FormRequest is recommended).
For example, to validate all items are emails, not long of 20 characters and there are at least 3 of them, you can use:
use Spatie\ValidationRules\Rules\Delimited;
// ...
public function rules()
{
return [
'emails' => [(new Delimited('email|max:20'))->min(3)],
];
}
The constructor of the validator accepts a validation rule string, a validation instance, or an array. That rules are used to validate all separate values; in this case, 'email|max:20'.

Answer 3

It's not a good practice to override the all() method to validate a field.
If you receive a comma separated String and not an array that you want to validate, but there is no common Method available, write your own.
in your App/Providers/ValidatorServiceProvider just add a new Validation:
public function boot()
{
Validator::extend('keywords', function ($attribute, $value, $parameters, $validator)
{
// put keywords into array
$keywords = explode(',', $value);
foreach($keywords as $keyword)
{
// do validation logic
if(strlen($keyword) < 3)
{
return false;
}
}
return true;
}
}
Now you can use this Validation Rule on any request if needed, it is reusable.
public function rules()
{
$rules = [
'title' => 'required|min:3|unique:subdomain_categories,title|unique:subdomain_keywords,keyword',
'description' => 'nullable',
'image' => 'required|image',
'keywords' => 'keywords',
];
return $rules;
}
If the validation pass and you want to make the keywords be accessible in your request as array, write your own method:
public function keywords ()
{
return explode(',', $this->get('keywords'));
}